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Can dplyr package be used for conditional mutating?
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220
Use ifelse
df %>%
mutate(g = ifelse(a == 2 | a == 5 | a == 7 | (a == 1 & b == 4), 2,
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How to use a variable for the key part of a map
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2 Answers
2
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import module from string variable
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288
The __import__ function can be a bit hard to understand.
If you change
i = __import__('matp...
Tell Ruby Program to Wait some amount of time
...following convenience syntax:
sleep(4.minutes)
# or, even longer...
sleep(2.hours); sleep(3.days) # etc., etc.
# or shorter
sleep(0.5) # half a second
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Transform DateTime into simple Date in Ruby on Rails
...ew.to_date
NoMethodError: undefined method 'to_date' for #<DateTime: -1/2,0,2299161>
from (irb):1
>> require 'active_support/core_ext'
=> true
>> DateTime.new.to_date
=> Mon, 01 Jan -4712
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Time complexity of Sieve of Eratosthenes algorithm
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Your n/2 + n/3 + n/5 + … n/97 is not O(n), because the number of terms is not constant. [Edit after your edit: O(n2) is too loose an upper bound.] A loose upper-bound is n(1+1/2+1/3+1/4+1/5+1/6+…1/n) (sum of reciprocals of all n...
How to count the number of true elements in a NumPy bool array
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265
You have multiple options. Two options are the following.
numpy.sum(boolarr)
numpy.count_nonz...
Maven check for updated dependencies in repository
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287
The Maven Versions plugin and its display-dependency-updates mojo are what you're looking for:...
NameError: global name 'xrange' is not defined in Python 3
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You are trying to run a Python 2 codebase with Python 3. xrange() was renamed to range() in Python 3.
Run the game with Python 2 instead. Don't try to port it unless you know what you are doing, most likely there will be more problems beyond xrange() vs. ...
git rebase, keeping track of 'local' and 'remote'
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TL;DR;
To summarize (As Benubird comments), when:
git checkout A
git rebase B # rebase ...